Code:#include <iostream> using namespace std; char isVowel(char ch); int main() { char ch; cout << "Please enter a letter from the alphabet: "; cin >> ch; cout<<"the letter you have entered is: isVowel(ch)"; return 0; } char isVowel(char x) { if (char ch = 'a') cout << "A Vowel" <<endl; else cout << "Not a vowel" <<endl; return 1; }